This invention relates to the method and means for entry of water to the water distribution system for evaporative pads in fixed or moveable evaporative coolers.
One form of evaporative air cooler consists of a cabinet having four or more sides at least one of which contains an absorptive pad in which is contained a fibrous absorption material, a water sump, a pump, water distribution system for wetting the absorption pad, and a fan and motor assembly for drawing air through the wetted absorbent material contained in the pad. The successful operation of such an evaporative cooler relies on water being distributed to the absorptive pads in sufficient quantities and in a consistently uniform manner along the pads. The cooler must have all parts of the absorptive pads constantly wet to perform satisfactorily.
Some of the practical difficulties encountered in this type of cooler are the problems of achieving uniformity of water distribution to all parts of the absorptive pad, and the tendency of water distribution systems to clog with foreign material.
The known methods of water distribution vary considerably. One such existing system pumps the water to a conduit under the cabinet lid with a plurality of holes, which in turn distribute the water into a second distributor, generally in the form of a trough, at the top of the filter pad frame. The holes in the distributor are relatively small and are frequently blocked. While it is possible to arrange for the entry point of water to the distribution system to be at the corners of the cooler, uniformity of water distribution is poor due to the small holes required and variations in flow to the holes from an out of level installation.
Excessive water in parts of the pad can result in water pulling off the filter pads and entering the fan. A deficiency of water in another part of the pad will result in reduced water evaporation and the entry of hot air directly into the cooler thereby diluting air that has been fully cooled by the pads and reducing the cooling capacity of the cooler.
In other systems the pump is connected via a conduit or conduits to a water distributor or distributors, which distribute water to a spreader bar or bars with a plurality of open channels, mounted close to the underside of the cooler lid. One example of such a system is the subject of Australian Patent No. 536805 in the name of the present applicant. This device provides for uniformity of water distribution and resistance to clogging, but requires a central water entry point for the distribution system to each evaporative pad. These systems are less prone to blockages and can tolerate a much greater degree of out of level installation before the uniformity of water distribution is affected. However, since these systems have separate conduits to distributors on each of the absorbent pads, they are relatively expensive and are susceptible to variations in flow to each of the distributors should there be a variation in water pressure in the water piping elsewhere in the cooler.
Since these system require a central water entry point to each of the water distributors, water entry piping is necessarily routed across the air stream of each absorptive pad, and requires a connection to the water spreader inside the airflow space of the cooler. This arrangement has the potential to interfere with the airstream through the pads. Should any failure occur with the water pipe connections in the cooler space or at the connection to the water spreaders, water in large quantities would be introduced into the airstream entering the building. The tendency and consequence of these deficiencies is more pronounced in coolers constructed with an axial fan, rather than a centrifugal fan, since there will always be a direct path between the point of failure and the entry point of the fan.
In all known current water supply and distribution systems, it is necessary to clean the system and remove blockages from inside the body of the evaporative cooler. This has the disadvantage of requiring partial dismantling of the evaporative cooler to gain access to the components which may be blocked. Accurate and complete re-assembly is necessary for the evaporative cooler to operate satisfactorily after clearing the blockage.
The object of the present invention is to provide an improved water entry and supply to the water distribution system of an evaporative cooler, which ameliorates the restrictions and deficiencies of the currently available systems.
According to one aspect the present invention provides a water entry system for the water distribution system of an evaporative cooler, said water entry system includes conduit means adapted to convey water from a pump of the evaporative cooler to at least one uppermost corner of said evaporative cooler, said at least one corner includes a capped water entry point adapted to output a substantially uniform curtain of water to at least one open channel for conveying water from the water entry system to the water spreader system of the cooler.